Registers
| Old3DS | Name | Address | Width | Used by |
|---|---|---|---|---|
| Yes | PDN_SHAREDWRAM_32K_DATA<0-7> | 0x10140000 | 1*8 | Boot11, Process9, DSP Services |
| Yes | PDN_SHAREDWRAM_32K_CODE<0-7> | 0x10140008 | 1*8 | Boot11, Process9, DSP Services |
| Yes | ARM11 interrupt related. | 0x10140104 | 1 | Kernel11. |
| Yes | 0x10140108 | 2 | TwlBg | |
| Yes | Camera related? | 0x10140180 | 1 | TwlBg |
| Yes | PDN_SPI_CNT | 0x101401C0 | 4 | SPI Services, TwlBg |
| Yes | PDN_GPU_STATUS? | 0x10141000 | 4 | Kernel11, TwlBg |
| Yes | PDN_PTM_0 | 0x10141008 | 4 | PTM Services |
| Yes | PDN_PTM_1 | 0x1014100C | 4 | PTM Services, TwlBg |
| Yes | PDN_TWLMODE | 0x10141100 | 2 | TwlProcess9, TwlBg |
| Yes | TwlMode related? | 0x10141104 | 2 | TwlBg |
| Yes | ? | 0x10141108 | 2 | TwlBg |
| Yes | PDN_WIFI? | 0x1014110C | 1 | |
| Yes | ? | 0x10141110 | 2 | TwlBg |
| Yes | ? | 0x10141112 | 2 | TwlBg |
| Yes | PDN_CODEC_0 | 0x10141114 | 2 | CODEC Services, TwlBg |
| Yes | PDN_CODEC_1 | 0x10141116 | 2 | CODEC Services, TwlBg |
| Yes | ? | 0x10141118 | 1 | TwlBg |
| Yes | ? | 0x10141119 | 1 | TwlBg |
| Yes | ? | 0x10141120 | 1 | TwlBg |
| Yes | PDN_WIFI_CNT | 0x10141180 | 1 | |
| Yes | PDN_HID_CNT | 0x101411C0 | 1 | |
| Yes | PDN_GPU_CNT | 0x10141200 | 4 | Boot11, Kernel11 |
| Yes | PDN_GPU_CNT2 | 0x10141204 | 4 | Boot11, Kernel11 |
| Yes | PDN_GPU_CNT3 | 0x10141210 | 2 | Kernel11, TwlBg |
| Yes | PDN_CODEC_CNT | 0x10141220 | 1 | Boot11, TwlBg |
| Yes | PDN_CAMERA_CNT | 0x10141224 | 1 | |
| Yes | SharedWram/DSP related. | 0x10141230 | 1 | Process9 |
| Yes | ? | 0x10141FFC | 4 |
PDN_SPI_CNT
| Bit | Description |
|---|---|
| 0 | Enable SPI Registers 0x10160000. |
| 1 | Enable SPI Registers 0x10142000. |
| 2 | Enable SPI Registers 0x10143800. |
PDN_SHAREDWRAM_32K_DATA
Used for mapping 32K chunks of shared WRAM for DSP data.
| Bits | Description |
|---|---|
| 0-1 | Master (0=ARM9?, 1=ARM11?, 2 or 3=DSP/data) |
| 2-4 | Offset (0..7) (slot 0..7) (LSB of address in 32Kbyte units) |
| 5-6 | Not used (0) |
| 7 | Enable (0=Disable, 1=Enable) |
PDN_SHAREDWRAM_32K_CODE
Used for mapping 32K chunks of shared WRAM for DSP data.
| Bits | Description |
|---|---|
| 0-1 | Master (0=ARM9?, 1=ARM11?, 2 or 3=DSP/code) |
| 2-4 | Offset (0..7) (slot 0..7) (LSB of address in 32Kbyte units) |
| 5-6 | Not used (0) |
| 7 | Enable (0=Disable, 1=Enable) |
PDN_WIFI_CNT
Bit0: Enable wifi.
PDN_HID_CNT
Bit0: Enable HID Registers.
PDN_TWLMODE
The very last 3DS-mode register poke the TWL_FIRM Process9 does before it gets switched into TWL-mode, is writing 0x8000 to this register. Before writing this register, TWL Process9 waits for the value of this register to become non-zero. The Process9 code for this runs from ITCM, since switching into TWL-mode includes remapping all ARM9 physical memory.
Writing 0x8000 to here from the ARM9 with NATIVE_FIRM running doesn't seem to do anything, other reg-pokes likely need done first.
PDN_GPU_CNT
This one seems to control the LCD/GPU/Backlight.
Bit0: Enable GPU registers at 0x10400000+. Bit16: Turn on LCD backlight.
PDN_GPU_CNT2
Bit0: Power on GPU?
PDN_CODEC
The following is the only time the ARM11 CODEC module uses any 0x1EC41XXX registers. In one case CODEC module clears bit1 in register 0x1EC41114, in the other case CODEC module sets bit1 in registers 0x1EC41114 and 0x1EC41116.
PDN_CODEC_CNT
This is the power register used for the PDN CODEC service.
bit0 = unknown, bit1 = turn on/off DSP, rest = always 0.
PDN_CAMERA_CNT
This is the power register used for the PDN camera service.
bit0 = unknown, bit1 = turn on/off cameras, rest = always 0.